/**
 * This interface represents a presence channel.
 */
class PresenceChannel {
    /**
     * Register a callback to be called anytime the member list changes.
     */
    here(callback) {}

    /**
     * Listen for someone joining the channel.
     */
    joining(callback) {}

    /**
     * Listen for someone leaving the channel.
     */
    leaving(callback) {}
}
